That is interesting, thank you. I will probably leave things as they are for now. Details of the DL 103GL follow;
1990 : DL 103 GL (Gold Limited) – special black housing, output 0.25mV, 40ohms, spherical stylus, 5cu, VTF 2.5 +/- 0.3grams, coils 4N High Purity Gold Wire 99.99%, ltd. production of 2000 – 50000 Yen.
Mine has been refurbished as described in my original post. Clearly the shibata diamond needs less VTF.
All the best.